HONG KONG–Bitter melon (Momordica charantia) reduced adiposity in rats on a high-fat diet, according to researchers at the University of Hong Kong who published their work in the April edition of the Journal of Nutrition (133, 4:1088-93, 2003) (www.nutrition.org). Researchers noted that while bitter melon has recognized hypoglycemic effects, it had not previously been investigated for its effect on rats fed a hyperinsulinemic, high-fat diet.
From a dose-response study, researchers noted rats fed a high-fat diet in combination with freeze-dried bitter melon juice exhibited improved oral glucose tolerance. They also reported that rats taking the supplement had less visceral fat mass than rats taking a high-fat diet alone.
In a subsequent experiment, rats habitually fed a high-fat diet either continued to consume the diet (control group) or were switched to one of three diets: 1) high-fat plus bitter melon; 2) low-fat; or 3) low-fat plus bitter melon. After seven weeks, rats switched to the high-fat, bitter melon diet gained less weight and had less visceral fat than the rats on the high-fat diet alone.
Researchers noted that adding bitter melon did not change apparent fat absorption, although it did improve insulin resistance, lower serum insulin and leptin, and raise serum free fatty acid concentration. They concluded bitter melon reduced body fat and appeared to have multiple influences on glucose and lipid metabolism that counteracted the negative effects of the high-fat diet.